I want to show an image from an URL with a certain width and height even if it has a different size ratio. So I want to resize (maintaining the ratio) and then cut the image to the size I want. I can resize with html img property and I can cut with background-image. How can I do both? Example: This image: Has the size 800x600 pixels and I want to show like an image of 200x100 pixels With img I can resize the image 200x150px: <img style="width: 200px; height: 150px;" src="http://i.stack.imgur.com/wPh0S.jpg"> That gives me this: <img style="width: 200px; height: 150px;" src="https://i.stack.imgur.com/wPh0S.jpg"> And with background-image I can cut the image 200x100 pixels. <div style="background-image: url('https://i.stack.imgur.com/wPh0S.jpg'); width:200px; height:100px; background-position:center;"> </div> Gives me: <div style="background-image:url('https://i.stack.imgur.com/wPh0S.jpg'); width:200px; height:100px; background-position:center;"> </div> How can I do both? Resize the image and then cut it the size I want?
当前回答
你也可以使用一个叫做Croppie的工具来裁剪图片…
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
<link href="https://foliotek.github.io/Croppie/croppie.css" rel="stylesheet" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"> </script>
<script src="https://foliotek.github.io/Croppie/croppie.js"> </script>
<script src="https://foliotek.github.io/Croppie/bower_components/exif-js/exif.js"> </script>
<style>
#page {
background: #ffffff;
padding: 20px;
margin: 20px;
}
#demo-basic {
width: 600px;
height: 600px;
}
</style>
</head>
<body>
<h1>Crop Image Demo</h1>
<input id="upload" type="file" />
<br />
<div id="page">
<div id="demo-basic"></div>
</div>
<input id="upload-result" type="button" value="Crop Image"/>
<br />
<img id="cropped-result" src=""/>
<script>
var $uploadCrop;
$("#upload").on("change", function () { readFile(this); show(); });
$("#upload-result").on("click", function (ev) {
$uploadCrop.croppie("result", {
type: "canvas",
size: "viewport"
}).then(function (resp) {
$("#cropped-result").attr("src", resp);
});
});
function show() {
$uploadCrop = $("#demo-basic").croppie({
viewport: { width: 100, height: 100 },
boundary: { width: 300, height: 300 },
enableResize: true,
enableOrientation: true,
mouseWheelZoom: 'ctrl',
enableExif: true
});
}
function readFile(input) {
if (input.files && input.files[0]) {
var reader = new FileReader();
reader.onload = function (e) {
$("#demo-basic").addClass("ready");
$uploadCrop.croppie("bind", {
url: e.target.result
}).then(function () {
console.log("jQuery bind complete");
});
}
reader.readAsDataURL(input.files[0]);
}
else {
alert("Sorry - you're browser doesn't support the FileReader API");
}
}
</script>
</body>
</html>
其他回答
你也可以使用一个叫做Croppie的工具来裁剪图片…
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title></title>
<link href="https://foliotek.github.io/Croppie/croppie.css" rel="stylesheet" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"> </script>
<script src="https://foliotek.github.io/Croppie/croppie.js"> </script>
<script src="https://foliotek.github.io/Croppie/bower_components/exif-js/exif.js"> </script>
<style>
#page {
background: #ffffff;
padding: 20px;
margin: 20px;
}
#demo-basic {
width: 600px;
height: 600px;
}
</style>
</head>
<body>
<h1>Crop Image Demo</h1>
<input id="upload" type="file" />
<br />
<div id="page">
<div id="demo-basic"></div>
</div>
<input id="upload-result" type="button" value="Crop Image"/>
<br />
<img id="cropped-result" src=""/>
<script>
var $uploadCrop;
$("#upload").on("change", function () { readFile(this); show(); });
$("#upload-result").on("click", function (ev) {
$uploadCrop.croppie("result", {
type: "canvas",
size: "viewport"
}).then(function (resp) {
$("#cropped-result").attr("src", resp);
});
});
function show() {
$uploadCrop = $("#demo-basic").croppie({
viewport: { width: 100, height: 100 },
boundary: { width: 300, height: 300 },
enableResize: true,
enableOrientation: true,
mouseWheelZoom: 'ctrl',
enableExif: true
});
}
function readFile(input) {
if (input.files && input.files[0]) {
var reader = new FileReader();
reader.onload = function (e) {
$("#demo-basic").addClass("ready");
$uploadCrop.croppie("bind", {
url: e.target.result
}).then(function () {
console.log("jQuery bind complete");
});
}
reader.readAsDataURL(input.files[0]);
}
else {
alert("Sorry - you're browser doesn't support the FileReader API");
}
}
</script>
</body>
</html>
我最近需要这样做。我想做一个缩略图链接到NOAA的图表。由于他们的图形可以随时改变，我希望我的缩略图也能随之改变。但他们的图表有一个问题:它在顶部有一个巨大的白色边框，所以如果你只是缩放它来制作缩略图，你最终会在文档中出现多余的空白。
以下是我的解决方法:
http://sealevel.info/example_css_scale_and_crop.html
首先我需要做一点算术。来自NOAA的原始图像是960 × 720像素，但前70个像素是一个多余的白色边界区域。我需要一个348 × 172的缩略图，顶部没有额外的边界区域。这意味着原始图像的期望部分是720 - 70 = 650像素高。我需要将其缩小到172像素，即172 / 650 = 26.5%。这意味着需要从缩放图像的顶部删除70 = 19行的26.5%的像素。
So…
设置高度= 172 + 19 = 191像素: 身高= 191 设置底部边距为-19像素(将图像缩短为172像素高): margin-bottom: -19像素 设置顶部位置为-19像素(将图像向上移动，以便顶部19像素的行溢出并隐藏，而不是底部的行): 前:-19像素
生成的HTML如下所示:
<a href="…" style="display:inline-block;overflow:hidden">
<img width=348 height=191 alt=""
style="border:0;position:relative;margin-bottom:-19px;top:-19px"
src="…"></a>
如您所见，我选择样式包含<a>标记，但您可以样式包含<div>。
这种方法的一个缺点是，如果您显示边界，顶部的边界将会丢失。因为我使用border=0，所以这对我来说不是问题。
有像Filestack这样的服务可以帮你做这件事。
它们获取你的图像url，并允许你使用url参数来调整它的大小。这很简单。
将图像大小调整为200x100，但保持纵横比后，图像将如下所示
整个url看起来像这样
https://process.filestackapi.com/AhTgLagciQByzXpFGRI0Az/resize=width:200/crop=d:[0,25,200,100]/https://i.stack.imgur.com/wPh0S.jpg
但重要的是
resize=width:200/crop=d:[0,25,200,100]
生活例子: https://jsfiddle.net/de4Lt57z/
HTML:
<div class="crop">
<img src="example.jpg" alt="..." />
</div>
CSS:
.crop img{
width:400px;
height:300px;
position: absolute;
clip: rect(0px,200px, 150px, 0px);
}
解释: 在这里，图像是根据图像的宽度和高度值调整大小。裁剪是通过剪辑属性完成的。
有关剪辑属性的详细信息请参见: http://tympanus.net/codrops/2013/01/16/understanding-the-css-clip-property/
您可以将img标记放在div标记中，但我建议不要在浏览器中缩放图像。它在大多数时候都做得很糟糕，因为浏览器的缩放算法非常简单。最好先在Photoshop或ImageMagick中进行缩放，然后将其漂亮地提供给客户端。
